0

賃借人、部門、基準の3つのモデルのアプリケーションがあります。

# app/models/department.rb

class Department < ActiveRecord::Base
  attr_accessible :name, :abbr

  has_many :renter_departments
  has_many :renters, :through => :renter_departments
end

と

# app/models/criterium.rb

class Criterium < ActiveRecord::Base
  attr_accessible :name

  has_many :renter_criteria
  has_many :renters, :through => :renter_criteria
end

レンターモデルで2つのスコープを作成して、部門別および基準別に賃借人を検索できるようにしようとしています。

これが私が持っているコードです：

# app/models/renter.rb

class Renter < ActiveRecord::Base

  # Relationships
  has_many :renter_departments
  has_many :renter_criteria
  has_many :departments, :through => :renter_departments
  has_many :criteria, :through => :renter_criteria

  # Scopes
  scope :from_department, lambda { |abbr| joins(:departments).where("abbr = ?", abbr) }
  scope :has_criterium, lambda { |criterium| joins(:criteria).where("name = ?", criterium) }

end

使用する

Renter.from_department("SCS")

また

Renter.has_criterium("Economic considerations")

単独で動作します。しかし、私がそれらを連鎖させようとすると、

Renter.from_department("SCS").has_criterium("Economic considerations")

次のようなエラーが発生します。

  Renter Load (0.3ms)  SELECT "renters".* FROM "renters" INNER JOIN "renter_departments" ON "renter_departments"."renter_id" = "renters"."id" INNER JOIN "departments" ON "departments"."id" = "renter_departments"."department_id" INNER JOIN "renter_criteria" ON "renter_criteria"."renter_id" = "renters"."id" INNER JOIN "criteria" ON "criteria"."id" = "renter_criteria"."criterium_id" WHERE (abbr = 'SCS') AND (name = 'Economic considerations')
SQLite3::SQLException: ambiguous column name: name: SELECT "renters".* FROM "renters" INNER JOIN "renter_departments" ON "renter_departments"."renter_id" = "renters"."id" INNER JOIN "departments" ON "departments"."id" = "renter_departments"."department_id" INNER JOIN "renter_criteria" ON "renter_criteria"."renter_id" = "renters"."id" INNER JOIN "criteria" ON "criteria"."id" = "renter_criteria"."criterium_id" WHERE (abbr = 'SCS') AND (name = 'Economic considerations')
ActiveRecord::StatementInvalid: SQLite3::SQLException: ambiguous column name: name: SELECT "renters".* FROM "renters" INNER JOIN "renter_departments" ON "renter_departments"."renter_id" = "renters"."id" INNER JOIN "departments" ON "departments"."id" = "renter_departments"."department_id" INNER JOIN "renter_criteria" ON "renter_criteria"."renter_id" = "renters"."id" INNER JOIN "criteria" ON "criteria"."id" = "renter_criteria"."criterium_id" WHERE (abbr = 'SCS') AND (name = 'Economic considerations')

さらに、

>> Renter.from_department("SCS").class
=> ActiveRecord::Relation
>> Renter.has_criterium("Economic considerations").class
=> ActiveRecord::Relation

私が間違っていることについて何か考えはありますか？

4

2 に答える 2

2

name結合しているテーブルには複数の列があります。句WHEREを使用するrenters.nameか、departments.nameまたは適切なname列を持つテーブルを作成します。

于 2012-05-01T00:01:39.963 に答える
1

スコープでテーブル名を参照する必要があります。

scope :from_department, lambda { |abbr| joins(:departments).where("departments.abbr = ?", abbr) }
scope :has_criterium, lambda { |criterium| joins(:criteria).where("criteria.name = ?", criterium) }
于 2012-05-01T00:10:17.950 に答える